"The great thing is, all sorts of hysterical things come out of it," McCartney said of his work with West. "I mean, there's a lot of people think Kanye discovered me. And that's not a joke."

McCartney also touched on the creation of "Four Five Seconds," his 2015 collaboration with Rihanna and West that would become his biggest hit single in 32 years.

McCartney told GQ that he didn't recognize his contribution to the finished product of "Four Five Seconds" until he reached out to West and learned that an acoustic guitar riff he had laid down in a studio session was "sped up and consequently raised in pitch" as the backing track.

The former Beatle also talked about his first time meeting West in 2008, when McCartney was coming off an acrimonious divorce from his second wife, Heather Mills, and West was going through the breakup that inspired his fourth album, "808s & Heartbreak."

"I'd just gone through my divorce, and I was kind of a little bit raw from it, and I said something to him about it, and he'd just broken up with someone," McCartney said. "And he just pulled out his phone and played this great little track—I don't even remember what it's called, but it's one of his famous ones. So I sort of liked him, and I liked this tune."